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-rw-r--r--man/systemd.exec.xml29
-rw-r--r--src/basic/capability-util.c71
-rw-r--r--src/basic/capability-util.h15
-rw-r--r--src/basic/missing.h16
-rw-r--r--src/core/dbus-execute.c23
-rw-r--r--src/core/execute.c100
-rw-r--r--src/core/execute.h4
-rw-r--r--src/core/load-fragment-gperf.gperf.m43
-rw-r--r--src/core/load-fragment.c29
-rw-r--r--src/core/load-fragment.h2
-rw-r--r--src/core/main.c10
-rw-r--r--src/core/unit.c2
-rw-r--r--src/import/import-common.c4
-rw-r--r--src/nspawn/nspawn.c2
-rw-r--r--src/test/test-capability.c68
-rw-r--r--src/test/test-execute.c16
-rw-r--r--src/test/test-unit-file.c41
-rw-r--r--test/test-execute/exec-capabilityambientset-merge.service9
-rw-r--r--test/test-execute/exec-capabilityambientset.service8
19 files changed, 372 insertions, 80 deletions
diff --git a/man/systemd.exec.xml b/man/systemd.exec.xml
index 5f98ef163c..f0f77c5091 100644
--- a/man/systemd.exec.xml
+++ b/man/systemd.exec.xml
@@ -807,6 +807,35 @@
</varlistentry>
<varlistentry>
+ <term><varname>AmbientCapabilities=</varname></term>
+
+ <listitem><para>Controls which capabilities to include in the
+ ambient capability set for the executed process. Takes a
+ whitespace-separated list of capability names as read by
+ <citerefentry project='mankier'><refentrytitle>cap_from_name</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ e.g. <constant>CAP_SYS_ADMIN</constant>,
+ <constant>CAP_DAC_OVERRIDE</constant>,
+ <constant>CAP_SYS_PTRACE</constant>. This option may appear more than
+ once in which case the ambient capability sets are merged.
+ If the list of capabilities is prefixed with <literal>~</literal>, all
+ but the listed capabilities will be included, the effect of the
+ assignment inverted. If the empty string is
+ assigned to this option, the ambient capability set is reset to
+ the empty capability set, and all prior settings have no effect.
+ If set to <literal>~</literal> (without any further argument), the
+ ambient capability set is reset to the full set of available
+ capabilities, also undoing any previous settings. Note that adding
+ capabilities to ambient capability set adds them to the process's
+ inherited capability set.
+ </para><para>
+ Ambient capability sets are useful if you want to execute a process
+ as a non-privileged user but still want to give it some capabilities.
+ Note that in this case option <constant>keep-caps</constant> is
+ automatically added to <varname>SecureBits=</varname> to retain the
+ capabilities over the user change.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
<term><varname>SecureBits=</varname></term>
<listitem><para>Controls the secure bits set for the executed
process. Takes a space-separated combination of options from
diff --git a/src/basic/capability-util.c b/src/basic/capability-util.c
index fef722b6f2..49c2d61afe 100644
--- a/src/basic/capability-util.c
+++ b/src/basic/capability-util.c
@@ -96,7 +96,62 @@ unsigned long cap_last_cap(void) {
return p;
}
-int capability_bounding_set_drop(uint64_t drop, bool right_now) {
+int capability_update_inherited_set(cap_t caps, uint64_t set) {
+ unsigned long i;
+
+ /* Add capabilities in the set to the inherited caps. Do not apply
+ * them yet. */
+
+ for (i = 0; i < cap_last_cap(); i++) {
+
+ if (set & (UINT64_C(1) << i)) {
+ cap_value_t v;
+
+ v = (cap_value_t) i;
+
+ /* Make the capability inheritable. */
+ if (cap_set_flag(caps, CAP_INHERITABLE, 1, &v, CAP_SET) < 0)
+ return -errno;
+ }
+ }
+
+ return 0;
+}
+
+int capability_ambient_set_apply(uint64_t set, bool also_inherit) {
+ unsigned long i;
+ _cleanup_cap_free_ cap_t caps = NULL;
+
+ /* Add the capabilities to the ambient set. */
+
+ if (also_inherit) {
+ int r;
+ caps = cap_get_proc();
+ if (!caps)
+ return -errno;
+
+ r = capability_update_inherited_set(caps, set);
+ if (r < 0)
+ return -errno;
+
+ if (cap_set_proc(caps) < 0)
+ return -errno;
+ }
+
+ for (i = 0; i < cap_last_cap(); i++) {
+
+ if (set & (UINT64_C(1) << i)) {
+
+ /* Add the capability to the ambient set. */
+ if (prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, i, 0, 0) < 0)
+ return -errno;
+ }
+ }
+
+ return 0;
+}
+
+int capability_bounding_set_drop(uint64_t keep, bool right_now) {
_cleanup_cap_free_ cap_t after_cap = NULL;
cap_flag_value_t fv;
unsigned long i;
@@ -137,7 +192,7 @@ int capability_bounding_set_drop(uint64_t drop, bool right_now) {
for (i = 0; i <= cap_last_cap(); i++) {
- if (drop & ((uint64_t) 1ULL << (uint64_t) i)) {
+ if (!(keep & (UINT64_C(1) << i))) {
cap_value_t v;
/* Drop it from the bounding set */
@@ -176,7 +231,7 @@ finish:
return r;
}
-static int drop_from_file(const char *fn, uint64_t drop) {
+static int drop_from_file(const char *fn, uint64_t keep) {
int r, k;
uint32_t hi, lo;
uint64_t current, after;
@@ -196,7 +251,7 @@ static int drop_from_file(const char *fn, uint64_t drop) {
return -EIO;
current = (uint64_t) lo | ((uint64_t) hi << 32ULL);
- after = current & ~drop;
+ after = current & keep;
if (current == after)
return 0;
@@ -213,14 +268,14 @@ static int drop_from_file(const char *fn, uint64_t drop) {
return r;
}
-int capability_bounding_set_drop_usermode(uint64_t drop) {
+int capability_bounding_set_drop_usermode(uint64_t keep) {
int r;
- r = drop_from_file("/proc/sys/kernel/usermodehelper/inheritable", drop);
+ r = drop_from_file("/proc/sys/kernel/usermodehelper/inheritable", keep);
if (r < 0)
return r;
- r = drop_from_file("/proc/sys/kernel/usermodehelper/bset", drop);
+ r = drop_from_file("/proc/sys/kernel/usermodehelper/bset", keep);
if (r < 0)
return r;
@@ -257,7 +312,7 @@ int drop_privileges(uid_t uid, gid_t gid, uint64_t keep_capabilities) {
return log_error_errno(errno, "Failed to disable keep capabilities flag: %m");
/* Drop all caps from the bounding set, except the ones we want */
- r = capability_bounding_set_drop(~keep_capabilities, true);
+ r = capability_bounding_set_drop(keep_capabilities, true);
if (r < 0)
return log_error_errno(r, "Failed to drop capabilities: %m");
diff --git a/src/basic/capability-util.h b/src/basic/capability-util.h
index 6bbf7318fd..be41475441 100644
--- a/src/basic/capability-util.h
+++ b/src/basic/capability-util.h
@@ -29,10 +29,15 @@
#include "macro.h"
#include "util.h"
+#define CAP_ALL (uint64_t) -1
+
unsigned long cap_last_cap(void);
int have_effective_cap(int value);
-int capability_bounding_set_drop(uint64_t drop, bool right_now);
-int capability_bounding_set_drop_usermode(uint64_t drop);
+int capability_bounding_set_drop(uint64_t keep, bool right_now);
+int capability_bounding_set_drop_usermode(uint64_t keep);
+
+int capability_ambient_set_apply(uint64_t set, bool also_inherit);
+int capability_update_inherited_set(cap_t caps, uint64_t ambient_set);
int drop_privileges(uid_t uid, gid_t gid, uint64_t keep_capabilities);
@@ -46,3 +51,9 @@ static inline void cap_free_charpp(char **p) {
cap_free(*p);
}
#define _cleanup_cap_free_charp_ _cleanup_(cap_free_charpp)
+
+static inline bool cap_test_all(uint64_t caps) {
+ uint64_t m;
+ m = (UINT64_C(1) << (cap_last_cap() + 1)) - 1;
+ return (caps & m) == m;
+}
diff --git a/src/basic/missing.h b/src/basic/missing.h
index 880e724cb4..2d2785bead 100644
--- a/src/basic/missing.h
+++ b/src/basic/missing.h
@@ -1129,3 +1129,19 @@ static inline key_serial_t request_key(const char *type, const char *description
#ifndef KEY_SPEC_USER_KEYRING
#define KEY_SPEC_USER_KEYRING -4
#endif
+
+#ifndef PR_CAP_AMBIENT
+#define PR_CAP_AMBIENT 47
+#endif
+
+#ifndef PR_CAP_AMBIENT_IS_SET
+#define PR_CAP_AMBIENT_IS_SET 1
+#endif
+
+#ifndef PR_CAP_AMBIENT_RAISE
+#define PR_CAP_AMBIENT_RAISE 2
+#endif
+
+#ifndef PR_CAP_AMBIENT_CLEAR_ALL
+#define PR_CAP_AMBIENT_CLEAR_ALL 4
+#endif
diff --git a/src/core/dbus-execute.c b/src/core/dbus-execute.c
index 1f736b2686..c2238c8c43 100644
--- a/src/core/dbus-execute.c
+++ b/src/core/dbus-execute.c
@@ -293,9 +293,25 @@ static int property_get_capability_bounding_set(
assert(reply);
assert(c);
- /* We store this negated internally, to match the kernel, but
- * we expose it normalized. */
- return sd_bus_message_append(reply, "t", ~c->capability_bounding_set_drop);
+ return sd_bus_message_append(reply, "t", c->capability_bounding_set);
+}
+
+static int property_get_ambient_capabilities(
+ sd_bus *bus,
+ const char *path,
+ const char *interface,
+ const char *property,
+ sd_bus_message *reply,
+ void *userdata,
+ sd_bus_error *error) {
+
+ ExecContext *c = userdata;
+
+ assert(bus);
+ assert(reply);
+ assert(c);
+
+ return sd_bus_message_append(reply, "t", c->capability_ambient_set);
}
static int property_get_capabilities(
@@ -689,6 +705,7 @@ const sd_bus_vtable bus_exec_vtable[] = {
SD_BUS_PROPERTY("Capabilities", "s", property_get_capabilities, 0, SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("SecureBits", "i", bus_property_get_int, offsetof(ExecContext, secure_bits), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("CapabilityBoundingSet", "t", property_get_capability_bounding_set, 0, SD_BUS_VTABLE_PROPERTY_CONST),
+ SD_BUS_PROPERTY("AmbientCapabilities", "t", property_get_ambient_capabilities, 0, SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("User", "s", NULL, offsetof(ExecContext, user), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("Group", "s", NULL, offsetof(ExecContext, group), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("SupplementaryGroups", "as", NULL, offsetof(ExecContext, supplementary_groups), SD_BUS_VTABLE_PROPERTY_CONST),
diff --git a/src/core/execute.c b/src/core/execute.c
index 9b76861919..ac91568b63 100644
--- a/src/core/execute.c
+++ b/src/core/execute.c
@@ -737,12 +737,7 @@ static int enforce_user(const ExecContext *context, uid_t uid) {
/* Sets (but doesn't lookup) the uid and make sure we keep the
* capabilities while doing so. */
- if (context->capabilities) {
- _cleanup_cap_free_ cap_t d = NULL;
- static const cap_value_t bits[] = {
- CAP_SETUID, /* Necessary so that we can run setresuid() below */
- CAP_SETPCAP /* Necessary so that we can set PR_SET_SECUREBITS later on */
- };
+ if (context->capabilities || context->capability_ambient_set != 0) {
/* First step: If we need to keep capabilities but
* drop privileges we need to make sure we keep our
@@ -758,16 +753,24 @@ static int enforce_user(const ExecContext *context, uid_t uid) {
/* Second step: set the capabilities. This will reduce
* the capabilities to the minimum we need. */
- d = cap_dup(context->capabilities);
- if (!d)
- return -errno;
+ if (context->capabilities) {
+ _cleanup_cap_free_ cap_t d = NULL;
+ static const cap_value_t bits[] = {
+ CAP_SETUID, /* Necessary so that we can run setresuid() below */
+ CAP_SETPCAP /* Necessary so that we can set PR_SET_SECUREBITS later on */
+ };
- if (cap_set_flag(d, CAP_EFFECTIVE, ELEMENTSOF(bits), bits, CAP_SET) < 0 ||
- cap_set_flag(d, CAP_PERMITTED, ELEMENTSOF(bits), bits, CAP_SET) < 0)
- return -errno;
+ d = cap_dup(context->capabilities);
+ if (!d)
+ return -errno;
- if (cap_set_proc(d) < 0)
- return -errno;
+ if (cap_set_flag(d, CAP_EFFECTIVE, ELEMENTSOF(bits), bits, CAP_SET) < 0 ||
+ cap_set_flag(d, CAP_PERMITTED, ELEMENTSOF(bits), bits, CAP_SET) < 0)
+ return -errno;
+
+ if (cap_set_proc(d) < 0)
+ return -errno;
+ }
}
/* Third step: actually set the uids */
@@ -1856,6 +1859,8 @@ static int exec_child(
if (params->apply_permissions) {
+ int secure_bits = context->secure_bits;
+
for (i = 0; i < _RLIMIT_MAX; i++) {
if (!context->rlimit[i])
continue;
@@ -1866,28 +1871,71 @@ static int exec_child(
}
}
- if (context->capability_bounding_set_drop) {
- r = capability_bounding_set_drop(context->capability_bounding_set_drop, false);
+ if (!cap_test_all(context->capability_bounding_set)) {
+ r = capability_bounding_set_drop(context->capability_bounding_set, false);
if (r < 0) {
*exit_status = EXIT_CAPABILITIES;
return r;
}
}
+ /* This is done before enforce_user, but ambient set
+ * does not survive over setresuid() if keep_caps is not set. */
+ if (context->capability_ambient_set != 0) {
+ r = capability_ambient_set_apply(context->capability_ambient_set, true);
+ if (r < 0) {
+ *exit_status = EXIT_CAPABILITIES;
+ return r;
+ }
+
+ if (context->capabilities) {
+
+ /* The capabilities in ambient set need to be also in the inherited
+ * set. If they aren't, trying to get them will fail. Add the ambient
+ * set inherited capabilities to the capability set in the context.
+ * This is needed because if capabilities are set (using "Capabilities="
+ * keyword), they will override whatever we set now. */
+
+ r = capability_update_inherited_set(context->capabilities, context->capability_ambient_set);
+ if (r < 0) {
+ *exit_status = EXIT_CAPABILITIES;
+ return r;
+ }
+ }
+ }
+
if (context->user) {
r = enforce_user(context, uid);
if (r < 0) {
*exit_status = EXIT_USER;
return r;
}
+ if (context->capability_ambient_set != 0) {
+
+ /* Fix the ambient capabilities after user change. */
+ r = capability_ambient_set_apply(context->capability_ambient_set, false);
+ if (r < 0) {
+ *exit_status = EXIT_CAPABILITIES;
+ return r;
+ }
+
+ /* If we were asked to change user and ambient capabilities
+ * were requested, we had to add keep-caps to the securebits
+ * so that we would maintain the inherited capability set
+ * through the setresuid(). Make sure that the bit is added
+ * also to the context secure_bits so that we don't try to
+ * drop the bit away next. */
+
+ secure_bits |= 1<<SECURE_KEEP_CAPS;
+ }
}
/* PR_GET_SECUREBITS is not privileged, while
* PR_SET_SECUREBITS is. So to suppress
* potential EPERMs we'll try not to call
* PR_SET_SECUREBITS unless necessary. */
- if (prctl(PR_GET_SECUREBITS) != context->secure_bits)
- if (prctl(PR_SET_SECUREBITS, context->secure_bits) < 0) {
+ if (prctl(PR_GET_SECUREBITS) != secure_bits)
+ if (prctl(PR_SET_SECUREBITS, secure_bits) < 0) {
*exit_status = EXIT_SECUREBITS;
return -errno;
}
@@ -2114,6 +2162,7 @@ void exec_context_init(ExecContext *c) {
c->timer_slack_nsec = NSEC_INFINITY;
c->personality = PERSONALITY_INVALID;
c->runtime_directory_mode = 0755;
+ c->capability_bounding_set = CAP_ALL;
}
void exec_context_done(ExecContext *c) {
@@ -2517,12 +2566,23 @@ void exec_context_dump(ExecContext *c, FILE* f, const char *prefix) {
(c->secure_bits & 1<<SECURE_NOROOT) ? " noroot" : "",
(c->secure_bits & 1<<SECURE_NOROOT_LOCKED) ? "noroot-locked" : "");
- if (c->capability_bounding_set_drop) {
+ if (c->capability_bounding_set != CAP_ALL) {
unsigned long l;
fprintf(f, "%sCapabilityBoundingSet:", prefix);
for (l = 0; l <= cap_last_cap(); l++)
- if (!(c->capability_bounding_set_drop & ((uint64_t) 1ULL << (uint64_t) l)))
+ if (c->capability_bounding_set & (UINT64_C(1) << l))
+ fprintf(f, " %s", strna(capability_to_name(l)));
+
+ fputs("\n", f);
+ }
+
+ if (c->capability_ambient_set != 0) {
+ unsigned long l;
+ fprintf(f, "%sAmbientCapabilities:", prefix);
+
+ for (l = 0; l <= cap_last_cap(); l++)
+ if (c->capability_ambient_set & (UINT64_C(1) << l))
fprintf(f, " %s", strna(capability_to_name(l)));
fputs("\n", f);
diff --git a/src/core/execute.h b/src/core/execute.h
index be5be9f531..8649620830 100644
--- a/src/core/execute.h
+++ b/src/core/execute.h
@@ -155,7 +155,9 @@ struct ExecContext {
char **read_write_dirs, **read_only_dirs, **inaccessible_dirs;
unsigned long mount_flags;
- uint64_t capability_bounding_set_drop;
+ uint64_t capability_bounding_set;
+
+ uint64_t capability_ambient_set;
cap_t capabilities;
int secure_bits;
diff --git a/src/core/load-fragment-gperf.gperf.m4 b/src/core/load-fragment-gperf.gperf.m4
index 0408b9a829..29ab1b6b9e 100644
--- a/src/core/load-fragment-gperf.gperf.m4
+++ b/src/core/load-fragment-gperf.gperf.m4
@@ -47,7 +47,8 @@ $1.SyslogLevel, config_parse_log_level, 0,
$1.SyslogLevelPrefix, config_parse_bool, 0, offsetof($1, exec_context.syslog_level_prefix)
$1.Capabilities, config_parse_exec_capabilities, 0, offsetof($1, exec_context)
$1.SecureBits, config_parse_exec_secure_bits, 0, offsetof($1, exec_context)
-$1.CapabilityBoundingSet, config_parse_bounding_set, 0, offsetof($1, exec_context.capability_bounding_set_drop)
+$1.CapabilityBoundingSet, config_parse_capability_set, 0, offsetof($1, exec_context.capability_bounding_set)
+$1.AmbientCapabilities, config_parse_capability_set, 0, offsetof($1, exec_context.capability_ambient_set)
$1.TimerSlackNSec, config_parse_nsec, 0, offsetof($1, exec_context.timer_slack_nsec)
$1.NoNewPrivileges, config_parse_no_new_privileges, 0, offsetof($1, exec_context)
m4_ifdef(`HAVE_SECCOMP',
diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c
index cb553e1252..d3880b4e3c 100644
--- a/src/core/load-fragment.c
+++ b/src/core/load-fragment.c
@@ -38,6 +38,7 @@
#include "bus-internal.h"
#include "bus-util.h"
#include "cap-list.h"
+#include "capability-util.h"
#include "cgroup.h"
#include "conf-parser.h"
#include "cpu-set-util.h"
@@ -1024,7 +1025,7 @@ int config_parse_exec_secure_bits(const char *unit,
return 0;
}
-int config_parse_bounding_set(
+int config_parse_capability_set(
const char *unit,
const char *filename,
unsigned line,
@@ -1036,8 +1037,8 @@ int config_parse_bounding_set(
void *data,
void *userdata) {
- uint64_t *capability_bounding_set_drop = data;
- uint64_t capability_bounding_set, sum = 0;
+ uint64_t *capability_set = data;
+ uint64_t sum = 0, initial = 0;
bool invert = false;
const char *p;
@@ -1051,10 +1052,9 @@ int config_parse_bounding_set(
rvalue++;
}
- /* Note that we store this inverted internally, since the
- * kernel wants it like this. But we actually expose it
- * non-inverted everywhere to have a fully normalized
- * interface. */
+ if (strcmp(lvalue, "CapabilityBoundingSet") == 0)
+ initial = CAP_ALL; /* initialized to all bits on */
+ /* else "AmbientCapabilities" initialized to all bits off */
p = rvalue;
for (;;) {
@@ -1073,18 +1073,21 @@ int config_parse_bounding_set(
cap = capability_from_name(word);
if (cap < 0) {
- log_syntax(unit, LOG_ERR, filename, line, 0, "Failed to parse capability in bounding set, ignoring: %s", word);
+ log_syntax(unit, LOG_ERR, filename, line, 0, "Failed to parse capability in bounding/ambient set, ignoring: %s", word);
continue;
}
sum |= ((uint64_t) UINT64_C(1)) << (uint64_t) cap;
}
- capability_bounding_set = invert ? ~sum : sum;
- if (*capability_bounding_set_drop != 0 && capability_bounding_set != 0)
- *capability_bounding_set_drop = ~(~*capability_bounding_set_drop | capability_bounding_set);
+ sum = invert ? ~sum : sum;
+
+ if (sum == 0 || *capability_set == initial)
+ /* "" or uninitialized data -> replace */
+ *capability_set = sum;
else
- *capability_bounding_set_drop = ~capability_bounding_set;
+ /* previous data -> merge */
+ *capability_set |= sum;
return 0;
}
@@ -4002,7 +4005,7 @@ void unit_dump_config_items(FILE *f) {
{ config_parse_log_level, "LEVEL" },
{ config_parse_exec_capabilities, "CAPABILITIES" },
{ config_parse_exec_secure_bits, "SECUREBITS" },
- { config_parse_bounding_set, "BOUNDINGSET" },
+ { config_parse_capability_set, "BOUNDINGSET" },
{ config_parse_limit, "LIMIT" },
{ config_parse_unit_deps, "UNIT [...]" },
{ config_parse_exec, "PATH [ARGUMENT [...]]" },
diff --git a/src/core/load-fragment.h b/src/core/load-fragment.h
index a451fc164a..f0027a6b43 100644
--- a/src/core/load-fragment.h
+++ b/src/core/load-fragment.h
@@ -56,7 +56,7 @@ int config_parse_exec_cpu_sched_prio(const char *unit, const char *filename, uns
int config_parse_exec_cpu_affinity(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_exec_capabilities(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_exec_secure_bits(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
-int config_parse_bounding_set(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_capability_set(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_limit(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_bytes_limit(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_sec_limit(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
diff --git a/src/core/main.c b/src/core/main.c
index f9de54028e..7a428fcccf 100644
--- a/src/core/main.c
+++ b/src/core/main.c
@@ -117,7 +117,7 @@ static usec_t arg_runtime_watchdog = 0;
static usec_t arg_shutdown_watchdog = 10 * USEC_PER_MINUTE;
static char **arg_default_environment = NULL;
static struct rlimit *arg_default_rlimit[_RLIMIT_MAX] = {};
-static uint64_t arg_capability_bounding_set_drop = 0;
+static uint64_t arg_capability_bounding_set = CAP_ALL;
static nsec_t arg_timer_slack_nsec = NSEC_INFINITY;
static usec_t arg_default_timer_accuracy_usec = 1 * USEC_PER_MINUTE;
static Set* arg_syscall_archs = NULL;
@@ -644,7 +644,7 @@ static int parse_config_file(void) {
{ "Manager", "JoinControllers", config_parse_join_controllers, 0, &arg_join_controllers },
{ "Manager", "RuntimeWatchdogSec", config_parse_sec, 0, &arg_runtime_watchdog },
{ "Manager", "ShutdownWatchdogSec", config_parse_sec, 0, &arg_shutdown_watchdog },
- { "Manager", "CapabilityBoundingSet", config_parse_bounding_set, 0, &arg_capability_bounding_set_drop },
+ { "Manager", "CapabilityBoundingSet", config_parse_capability_set, 0, &arg_capability_bounding_set },
#ifdef HAVE_SECCOMP
{ "Manager", "SystemCallArchitectures", config_parse_syscall_archs, 0, &arg_syscall_archs },
#endif
@@ -1631,14 +1631,14 @@ int main(int argc, char *argv[]) {
if (prctl(PR_SET_TIMERSLACK, arg_timer_slack_nsec) < 0)
log_error_errno(errno, "Failed to adjust timer slack: %m");
- if (arg_capability_bounding_set_drop) {
- r = capability_bounding_set_drop_usermode(arg_capability_bounding_set_drop);
+ if (!cap_test_all(arg_capability_bounding_set)) {
+ r = capability_bounding_set_drop_usermode(arg_capability_bounding_set);
if (r < 0) {
log_emergency_errno(r, "Failed to drop capability bounding set of usermode helpers: %m");
error_message = "Failed to drop capability bounding set of usermode helpers";
goto finish;
}
- r = capability_bounding_set_drop(arg_capability_bounding_set_drop, true);
+ r = capability_bounding_set_drop(arg_capability_bounding_set, true);
if (r < 0) {
log_emergency_errno(r, "Failed to drop capability bounding set: %m");
error_message = "Failed to drop capability bounding set";
diff --git a/src/core/unit.c b/src/core/unit.c
index b977ac7f0c..e1bc6c75cb 100644
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -3231,7 +3231,7 @@ int unit_patch_contexts(Unit *u) {
ec->no_new_privileges = true;
if (ec->private_devices)
- ec->capability_bounding_set_drop |= (uint64_t) 1ULL << (uint64_t) CAP_MKNOD;
+ ec->capability_bounding_set &= ~(UINT64_C(1) << CAP_MKNOD);
}
cc = unit_get_cgroup_context(u);
diff --git a/src/import/import-common.c b/src/import/import-common.c
index a8551ca9e8..8a48bd7bf9 100644
--- a/src/import/import-common.c
+++ b/src/import/import-common.c
@@ -134,7 +134,7 @@ int import_fork_tar_x(const char *path, pid_t *ret) {
if (unshare(CLONE_NEWNET) < 0)
log_error_errno(errno, "Failed to lock tar into network namespace, ignoring: %m");
- r = capability_bounding_set_drop(~retain, true);
+ r = capability_bounding_set_drop(retain, true);
if (r < 0)
log_error_errno(r, "Failed to drop capabilities, ignoring: %m");
@@ -208,7 +208,7 @@ int import_fork_tar_c(const char *path, pid_t *ret) {
if (unshare(CLONE_NEWNET) < 0)
log_error_errno(errno, "Failed to lock tar into network namespace, ignoring: %m");
- r = capability_bounding_set_drop(~retain, true);
+ r = capability_bounding_set_drop(retain, true);
if (r < 0)
log_error_errno(r, "Failed to drop capabilities, ignoring: %m");
diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c
index a4e13bd6aa..d619206dd6 100644
--- a/src/nspawn/nspawn.c
+++ b/src/nspawn/nspawn.c
@@ -1482,7 +1482,7 @@ static int setup_journal(const char *directory) {
}
static int drop_capabilities(void) {
- return capability_bounding_set_drop(~arg_retain, false);
+ return capability_bounding_set_drop(arg_retain, false);
}
static int reset_audit_loginuid(void) {
diff --git a/src/test/test-capability.c b/src/test/test-capability.c
index fc8d3ffe0d..629bb63c81 100644
--- a/src/test/test-capability.c
+++ b/src/test/test-capability.c
@@ -20,6 +20,7 @@
#include <netinet/in.h>
#include <pwd.h>
#include <sys/capability.h>
+#include <sys/prctl.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <unistd.h>
@@ -66,8 +67,9 @@ static void show_capabilities(void) {
cap_free(text);
}
-static int setup_tests(void) {
+static int setup_tests(bool *run_ambient) {
struct passwd *nobody;
+ int r;
nobody = getpwnam("nobody");
if (!nobody) {
@@ -77,6 +79,18 @@ static int setup_tests(void) {
test_uid = nobody->pw_uid;
test_gid = nobody->pw_gid;
+ *run_ambient = false;
+
+ r = prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_CLEAR_ALL, 0, 0, 0);
+
+ /* There's support for PR_CAP_AMBIENT if the prctl() call
+ * succeeded or error code was something else than EINVAL. The
+ * EINVAL check should be good enough to rule out false
+ * positives. */
+
+ if (r >= 0 || errno != EINVAL)
+ *run_ambient = true;
+
return 0;
}
@@ -140,8 +154,53 @@ static void test_have_effective_cap(void) {
assert_se(!have_effective_cap(CAP_CHOWN));
}
+static void test_update_inherited_set(void) {
+ cap_t caps;
+ uint64_t set = 0;
+ cap_flag_value_t fv;
+
+ caps = cap_get_proc();
+ assert_se(caps);
+ assert_se(!cap_get_flag(caps, CAP_CHOWN, CAP_INHERITABLE, &fv));
+ assert(fv == CAP_CLEAR);
+
+ set = (UINT64_C(1) << CAP_CHOWN);
+
+ assert_se(!capability_update_inherited_set(caps, set));
+ assert_se(!cap_get_flag(caps, CAP_CHOWN, CAP_INHERITABLE, &fv));
+ assert(fv == CAP_SET);
+
+ cap_free(caps);
+}
+
+static void test_set_ambient_caps(void) {
+ cap_t caps;
+ uint64_t set = 0;
+ cap_flag_value_t fv;
+
+ caps = cap_get_proc();
+ assert_se(caps);
+ assert_se(!cap_get_flag(caps, CAP_CHOWN, CAP_INHERITABLE, &fv));
+ assert(fv == CAP_CLEAR);
+ cap_free(caps);
+
+ assert_se(prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_IS_SET, CAP_CHOWN, 0, 0) == 0);
+
+ set = (UINT64_C(1) << CAP_CHOWN);
+
+ assert_se(!capability_ambient_set_apply(set, true));
+
+ caps = cap_get_proc();
+ assert_se(!cap_get_flag(caps, CAP_CHOWN, CAP_INHERITABLE, &fv));
+ assert(fv == CAP_SET);
+ cap_free(caps);
+
+ assert_se(prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_IS_SET, CAP_CHOWN, 0, 0) == 1);
+}
+
int main(int argc, char *argv[]) {
int r;
+ bool run_ambient;
log_parse_environment();
log_open();
@@ -149,14 +208,19 @@ int main(int argc, char *argv[]) {
if (getuid() != 0)
return EXIT_TEST_SKIP;
- r = setup_tests();
+ r = setup_tests(&run_ambient);
if (r < 0)
return -r;
show_capabilities();
test_drop_privileges();
+ test_update_inherited_set();
+
fork_test(test_have_effective_cap);
+ if (run_ambient)
+ fork_test(test_set_ambient_caps);
+
return 0;
}
diff --git a/src/test/test-execute.c b/src/test/test-execute.c
index 753afadb0a..92857cb5e2 100644
--- a/src/test/test-execute.c
+++ b/src/test/test-execute.c
@@ -20,6 +20,7 @@
#include <grp.h>
#include <pwd.h>
#include <stdio.h>
+#include <sys/prctl.h>
#include <sys/types.h>
#include "fileio.h"
@@ -224,6 +225,20 @@ static void test_exec_capabilityboundingset(Manager *m) {
test(m, "exec-capabilityboundingset-invert.service", 0, CLD_EXITED);
}
+static void test_exec_capabilityambientset(Manager *m) {
+ int r;
+
+ /* Check if the kernel has support for ambient capabilities. Run
+ * the tests only if that's the case. Clearing all ambient
+ * capabilities is fine, since we are expecting them to be unset
+ * in the first place for the tests. */
+ r = prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_CLEAR_ALL, 0, 0, 0);
+ if (r >= 0 || errno != EINVAL) {
+ test(m, "exec-capabilityambientset.service", 0, CLD_EXITED);
+ test(m, "exec-capabilityambientset-merge.service", 0, CLD_EXITED);
+ }
+}
+
static void test_exec_privatenetwork(Manager *m) {
int r;
@@ -266,6 +281,7 @@ int main(int argc, char *argv[]) {
test_exec_umask,
test_exec_runtimedirectory,
test_exec_capabilityboundingset,
+ test_exec_capabilityambientset,
test_exec_oomscoreadjust,
test_exec_ioschedulingclass,
NULL,
diff --git a/src/test/test-unit-file.c b/src/test/test-unit-file.c
index 0b3630f77c..cd1e4e4698 100644
--- a/src/test/test-unit-file.c
+++ b/src/test/test-unit-file.c
@@ -28,6 +28,7 @@
#include <unistd.h>
#include "alloc-util.h"
+#include "capability-util.h"
#include "fd-util.h"
#include "fileio.h"
#include "hashmap.h"
@@ -625,8 +626,8 @@ static uint64_t make_cap(int cap) {
return ((uint64_t) 1ULL << (uint64_t) cap);
}
-static void test_config_parse_bounding_set(void) {
- /* int config_parse_bounding_set(
+static void test_config_parse_capability_set(void) {
+ /* int config_parse_capability_set(
const char *unit,
const char *filename,
unsigned line,
@@ -638,38 +639,38 @@ static void test_config_parse_bounding_set(void) {
void *data,
void *userdata) */
int r;
- uint64_t capability_bounding_set_drop = 0;
+ uint64_t capability_bounding_set = 0;
- r = config_parse_bounding_set(NULL, "fake", 1, "section", 1,
+ r = config_parse_capability_set(NULL, "fake", 1, "section", 1,
"CapabilityBoundingSet", 0, "CAP_NET_RAW",
- &capability_bounding_set_drop, NULL);
+ &capability_bounding_set, NULL);
assert_se(r >= 0);
- assert_se(capability_bounding_set_drop == ~make_cap(CAP_NET_RAW));
+ assert_se(capability_bounding_set == make_cap(CAP_NET_RAW));
- r = config_parse_bounding_set(NULL, "fake", 1, "section", 1,
+ r = config_parse_capability_set(NULL, "fake", 1, "section", 1,
"CapabilityBoundingSet", 0, "CAP_NET_ADMIN",
- &capability_bounding_set_drop, NULL);
+ &capability_bounding_set, NULL);
assert_se(r >= 0);
- assert_se(capability_bounding_set_drop == ~(make_cap(CAP_NET_RAW) | make_cap(CAP_NET_ADMIN)));
+ assert_se(capability_bounding_set == (make_cap(CAP_NET_RAW) | make_cap(CAP_NET_ADMIN)));
- r = config_parse_bounding_set(NULL, "fake", 1, "section", 1,
+ r = config_parse_capability_set(NULL, "fake", 1, "section", 1,
"CapabilityBoundingSet", 0, "",
- &capability_bounding_set_drop, NULL);
+ &capability_bounding_set, NULL);
assert_se(r >= 0);
- assert_se(capability_bounding_set_drop == ~((uint64_t) 0ULL));
+ assert_se(capability_bounding_set == UINT64_C(0));
- r = config_parse_bounding_set(NULL, "fake", 1, "section", 1,
+ r = config_parse_capability_set(NULL, "fake", 1, "section", 1,
"CapabilityBoundingSet", 0, "~",
- &capability_bounding_set_drop, NULL);
+ &capability_bounding_set, NULL);
assert_se(r >= 0);
- assert_se(capability_bounding_set_drop == (uint64_t) 0ULL);
+ assert_se(cap_test_all(capability_bounding_set));
- capability_bounding_set_drop = 0;
- r = config_parse_bounding_set(NULL, "fake", 1, "section", 1,
+ capability_bounding_set = 0;
+ r = config_parse_capability_set(NULL, "fake", 1, "section", 1,
"CapabilityBoundingSet", 0, " 'CAP_NET_RAW' WAT_CAP??? CAP_NET_ADMIN CAP'_trailing_garbage",
- &capability_bounding_set_drop, NULL);
+ &capability_bounding_set, NULL);
assert_se(r >= 0);
- assert_se(capability_bounding_set_drop == ~(make_cap(CAP_NET_RAW) | make_cap(CAP_NET_ADMIN)));
+ assert_se(capability_bounding_set == (make_cap(CAP_NET_RAW) | make_cap(CAP_NET_ADMIN)));
}
static void test_config_parse_rlimit(void) {
@@ -829,7 +830,7 @@ int main(int argc, char *argv[]) {
r = test_unit_file_get_set();
test_config_parse_exec();
- test_config_parse_bounding_set();
+ test_config_parse_capability_set();
test_config_parse_rlimit();
test_config_parse_pass_environ();
test_load_env_file_1();
diff --git a/test/test-execute/exec-capabilityambientset-merge.service b/test/test-execute/exec-capabilityambientset-merge.service
new file mode 100644
index 0000000000..64964380e2
--- /dev/null
+++ b/test/test-execute/exec-capabilityambientset-merge.service
@@ -0,0 +1,9 @@
+[Unit]
+Description=Test for AmbientCapabilities
+
+[Service]
+ExecStart=/bin/sh -x -c 'c=$$(grep "CapAmb:" /proc/self/status); test "$$c" = "CapAmb: 0000000000003000"'
+Type=oneshot
+User=nobody
+AmbientCapabilities=CAP_NET_ADMIN
+AmbientCapabilities=CAP_NET_RAW
diff --git a/test/test-execute/exec-capabilityambientset.service b/test/test-execute/exec-capabilityambientset.service
new file mode 100644
index 0000000000..d63f884ef8
--- /dev/null
+++ b/test/test-execute/exec-capabilityambientset.service
@@ -0,0 +1,8 @@
+[Unit]
+Description=Test for AmbientCapabilities
+
+[Service]
+ExecStart=/bin/sh -x -c 'c=$$(grep "CapAmb:" /proc/self/status); test "$$c" = "CapAmb: 0000000000003000"'
+Type=oneshot
+User=nobody
+AmbientCapabilities=CAP_NET_ADMIN CAP_NET_RAW
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-07-27 19:54:15 +0000